Frazier Glenn Cross, Jr., 73, is suspected of fatally shooting a 14-year-old Eagle Scout and his grandfather in the parking lot at the Jewish Community Center of Greater Kansas City campus in Overland Park then gunning down a woman at Village Shalom, a retirement community that is several blocks away from the center, law enforcement officials said.

KSHB reporter Andres Gutierrez told MSNBC that the suspect who was taken away in the back of a police car yelled “Heil Hitler” at onlookers.

A civil rights organization that tracks hate groups said it has long known about Cross, who is from Missouri.

The Southern Poverty Law Center says Cross is known to them using aliases — Glenn Miller or Frazier Glenn Miller — and is the former Grand Dragon of the Carolina Knights of the Ku Klux Klan.

The center sued Cross in the 1980s for intimidating African Americans, and he has had several run-ins with the law since then, including being accused of violating the terms of a court order that settled the lawsuit.

According to the SPLC, Cross quit high school as a senior to join the Army. In a 20-year Army career he had two tours in Vietnam and 13 years as a member of the elite Green Berets before he was forced to retire because of his Klan affiliation in 1979.

Later he went on to be active in a neo-Nazi group called “The Order” that advocated violence against Blacks and Jews among others, the SPLC said.

He even unsuccessfully ran in the Democratic primary for North Carolina governor in 1984 and as a Republican for a state Senate seat in 1987, the SPLC said.

According to The Associated Press, Miller was the subject of a nationwide manhunt in 1987 for violating the terms of his bond while appealing a North Carolina conviction for operating a paramilitary camp.

The search ended after federal agents found Miller and three other men in an Ozark mobile home, which was filled with hand grenades, automatic weapons and thousands of rounds of ammunition.